Roll stand

ABSTRACT

A roll stand has two lateral frames which are spaced apart and each of which has a window opening. A plurality of rolls extends between the lateral frames and each roll is journalled adjacent its opposite ends in chocks received in the window openings. A screw-down cross beam extends between the lateral frames at a location between the top of each frame and the uppermost roll. A screw-down mechanism is associated with each frame and comprises a nut fixedly mounted on the cross beam. A thrust member in screw threaded engagement with said nut and a drive mechanism mounted on said cross beam for imparting a rotary motion to said thrust member while permitting movement thereof relative to said nut. The cross beam in the screwed-down condition is thus braced against the upper part of the frame via the thrust members.

United States Patent Kersting ROLL STAND Emil Friedrich Kersting,Dusseldorf, Germany [73] Assignee: Maschinenfabrik Sack Gmbl-l,

Dusseldorf-Rath, Germany [22] Filed: July 8, 1974 [21] Appl. No.:486,606

[75] Inventor:

Primary E.\'aminer-Milton S. Mehr Attorney, Agent, or FirmJohn J.Dennemeyer [5 7] ABSTRACT A roll stand has two lateral frames which arespaced apart and each of which has a window opening. A plurality ofrolls extends between the lateral frames and each roll is journalledadjacent its opposite ends in chocks received in the window openings. Ascrewdown cross beam extends between the lateral frames at a locationbetween the top of each frame and the uppermost roll. A screw-downmechanism is associated with each frame and comprises a nut fixedlymounted on the cross beam. A thrust member in screw threaded engagementwith said nut and a drive mechanism mounted on said cross beam forimparting a rotary motion to said thrust member while permittingmovement thereof relative to said nut. The cross beam in thescrewed-down condition is thus braced against the upper part of theframe via the thrust members.

5 Claims, 3 Drawing Figures PATENTEB RAY I 31975 SHEET 1%? 3 mm MAY 1 34975 SHEET 2 BF 3 T in ROLL STAND The invention relates to screwdowngear for rolling mills with closed housings forming windows for theroller installation members and with a screwdown crossbeam following thescrewdown movements of the adjusting screws, which cross-beam may beinserted in the windows between the upper cross-bars of the housings andthe installation members of the upper rollers. A screwdown cross-beam ofthis type has the purpose either of facilitating the installation ofrollers of varying surface length, without having to move the housings(DT-PS 607 741), or of serving as a support member, following thescrewdown movements, for the power cylinder of a roll camber controldevice (DT-OS l 527 739).

Within the framework of the invention, a screwdown cross-beam of thistype is used for another purpose. It was based on the consideration thatthe normal construction of a roll stand, comprising two closed housingsand adjusting screws in the upper cross-bars of the housings foradjusting the upper roller, has certain drawbacks, connected with theweakening of the crosssections of the upper cross-bars of the housingsby the adjusting screws passing therethrough. This weakening of thecross-section is normally made up for by an accumulation of material onthe upper cross-bars in the region of the adjusting screws.Nevertheless, it is very difficult to adapt the bending behaviour oftheupper cross-bars to that of the lower cross-bars of the housings. Afurther drawback consists in that for the insertion of thescrew-threaded nuts in the upper cross-bars, the housings, which undercertain circumstances are very heavy, have to be machined on acorrespondingly heavy machine tool having a high cost per hour. Not onlymust bores be provided, but also flat bearing surfaces for theattachments of the screwdown gear, namely for the screwdown gearing andthe screwdown motors. Also, the expenditure for preparatory work, forexample for marking the heavy cast parts is not inconsiderable. Even ifthe housings are produced in a split construction, the machining of theupper cross-bars must take place when the housings are assembled.

Based on a rolling mill with closed housings, either cast in one unit orassembled from many parts, it is the object of the invention to relievethe upper cross-bars of the housings of their task of guiding theadjusting screws of the screwdown gear, in order to reduce machiningcosts on the housings to a minimum and in order to achieve roll housingswith a cross-section subjected to equal bending in the upper and lowercrossbars. This object is fulfilled according to the invention in thatthe adjusting screws, their threaded nuts and their motorized rotarydrives form a detachable unit with the screwdown cross-beam. Whilst theaforementioned drawbacks of the conventional stand construction, towhich the technical world hasclearly been long accustomed, are avoidedby the invention, an additional advantage is provided by the possibilityof easily detaching all parts belonging to the screwdown gear, namely,even the gearing and screwdown motors supported by the screwdowncross-beam. If a screwdown cross-beam according to the invention is keptin reserve, disturbances in the screwdown gearing may be removed in thefastest manner by simply exchanging the screwdown cross-beams.

It should be mentioned that in the case of another stand construction,namely the so-called tie-rod roll stands, the arrangement of screwdowngearing and motors or even hydraulic mechanisms on the individualvertically adjustable upper stand parts is known (DT-OS l 527 753).However, due to this the problem in question is not touched upon.

Should the roll stand, in particular as a four-high roll stand forrolling hot or cold sheet metal, be provided with an additionalhydraulic screwdown mechanism for automatically regulating the roll gap,then according to the invention, the hydraulic regulating cylinderstogether with their feed pipes may be supported by the screwdowncross-beam.

Theoretically, it is immaterial whether the screwdown cross-beam restsdirectly on the installation components of the upper roller, i.e. theadjusting screws are supported on the upper cross-bars of the housings,or whether, vice versa, the screwdown cross-beam rests directly on thecross-bars. However, if the roll stand is to be equipped with a cambercontrol device for the upper adjustable roller, whereby the screwdowncrossbeam is constructed to be resistant to bending as known per se andhydraulic power cylinders are fixed to the extended ends, which powercylinders are connected to auxiliary bearings for controlling the camberof the upper roller, located on the extended roll journals of the upperroll, then it is advisable for the screwdown cross-beam to rest directlyon the installation components. The regulating cylinders of an automaticroll gap regulator are then located between the adjusting screws and thecross-bars of the housings. Due to this, the known advantage is achievedthat both during actuation of the mechanical screwdown gear for a coarseadjustment and during roll gap corrections by the automatic roll gapregulator, the hydraulic power cylinders of the camber control devicefollow the movements of the upper roller and the pre-set counter bendingforce remains unchanged. Also, the screwdown cross-beam may be removedmore easily from the windows of the housings, when it rests directly onthe installation components of the upper roller by a continuous lowerbearing surface.

In order to secure the hydraulic regulating cylinders resting on theadjusting screws and thus supported by the screwdown cross-beam, intheir position, it is proposed according to the invention that theregulating cylinders are interconnected by a common connecting plateguided in the windows, on which connecting plate the pressure mediumfeed pipes and if necessary, also hydraulic pressure converters arelocated. Thus, the hydraulic control elements of the automatic roll gapregulator may be largely located on the connecting plate with the resultthat these parts requiring maintenance are also detachable together withthe screwdown cross-beam.

The further development of the positioning of the regulating cylindermakes it possible to flange-mount hydraulic units without pipes on theregulating cylinders, so that at the time of detaching the screwdowncross-beam, apart from the electric leads to the screwdown motor ormotors, only the flexible or pliable pipes carrying the hydraulicregulating magnitude, have to be released.

One embodiment of screwdown gear for rolling mills according to theinvention is illustrated in the drawing and in particular 3 FIG. 1 showsthe upper part of a four-high roll stand,

on the left in vertical section through one of the adjust ing screws, onthe right in elevation,

FIG. 2 is a section on line llll of FIG. 1 and P16. 3 shows a detail.

The illustrated four-high roll stand comprises two housings 2, in theassembled position, whereof the vertical housing posts areinterconnected by upper crossbars 2a. The housing, cross-bars 2a areinterconnected by a bridge 3. Of the set of rollers, an upper backingroll 4 and an upper working roll 5 are shown. The back ing roll 4 ismounted in installation components 6, which are guided in the windows 7formed by the housings 2.

Located between the installation components 6 and the upper cross-bars2a of the housings 2 is a screwdown cross-beam 8 passing through thewindows 7 and guided therein, which cross-beam is supported by way ofknife-edge bearings 9 on the installation components 6 of the upperroller 4. On each side of the housing, the screwdown cross-beam 8supports non-rotary threaded nuts 10 for screwdown adjusting screws 11(FIG. 2), which are inserted by their ends facing the cross-bars 2ainworm gears 12 such that they cannotrotate but are able to slide. Theworm gears 12 may be driven by worms 13, which are in turn drivenlaterally by a screwdown motor 14. The screwdown cross-beam 8 thussupports the mechanical screwdown gear for both sides of the housing, inorder to adjust the upper set of rolls 4, 5 to the desired roll gap withrespect to the lower set of rolls (not shown). if, in fact, the wormgear 12 is rotated, depending on the direction of rotation, theadjusting screws 11 travel either upwards out of the screwdowncross-beam or vice versa, due to which the spacing of the installationcomponent 6 of the upper roller 4 from the cross-bars 2a of the housings2 is determined.

The arrangement of the adjusting screws 11 inside the screwdowncross-beam 8 has the result that the cross-bars 2a of the housings areno longer weakened by the previously required threaded bores for theadjusting screws and may have cross-sections undergoing equal bendingboth at the top and bottom.

The illustrated roll stand is also provided with hydraulic screwdowngear for an automatic roll gap regulation. For this, two pressure plates16 and 17, centered one in the other, are placed on each upper end face11a of the adjusting screws 11, whereof the'upper pressure plate 17respectively forms the means for centering the piston 18 of theregulating cylinder 20. Each regulating piston 20 is supported by meansof a pressure plate 21 on the housing side, against a cross-bar 2a.According to the regulating pressure pre-set by the regulating piston18, the pistons 18 carry out their regulating stroke inside theregulating cylinder 20, due to which a roll gap correction is undertakenby way of the adjusting screws 11, the threaded nuts 10 and thescrewdowncross-beam 8.

The regulating cylinders 20 are interconnected by a common connectingplate 22 guided vertically in the window 7, which plate 22, is providedwith bores 23 at the spacing A of the two adjusting screws 11, accordingto FIG. 3. The regulating pistons 18 are inserted in these bores 23 by astepped end, which is reduced in diameter, to slide in a limited mannerby the regulating stroke provided, because in the vicinity ofthe bores23, the connecting plate 22 is screwed to the underneath 20, as shown inFIG. 2.

Due to this, not only is the position of the regulating units resting onthe adjustingscrews 11 maintained, but on the contrary the connectingplate 22 may beused to I A particular advantage for supporting thecontrol meme, bers for the regulation in the form of pressure convert- 11 ers 24 and 25. These pressure converters may be flange-connecteddirectly tothe regulating cylinders 20 1 without pipes, since norelative movement occursjbe-j. tween the regulating cylinders and theconnecting plate. The pressure chamber 24a, for example of the jpressure converter 24, opens at its outlet directly into the channel 26of the associated regulating cylinder 20,, I The two converters 24, 25overlapping partly alon g their length and located one beside theotheruon the 1 1 f connecting 1 plate 22, serve, in the present case, in1 known manner, for changing over a regulating pressure produced bypressure oil to grease as the lastpressure medium in the regulatingcylinders 20.

With the screwdown cross-beam 8 constructed' ac cording to the inventionas a support both forthe me chanical as well as the hydraulicscrewdowngear, not F only are the housing cross-sections independent ofthe" I screwdown gear, but on the contrary all parts of the I Iscrewdown gear subject to wear and requiring mai ntef nance can bedismantled together with the screwdown" cross-beam 8.

The screwdown cross-beam 8 is constructed to be re. 7 sistant to bendingif the stand is intended t'ojbeprovided with a so-called camber controldevicefor at] f least the upper backing roll 4, as shown in FIG. 1. Asknown, the backing roll 4 is then provided with eio i tended journalends 4a, on each of which is located an q auxiliary bearing 30mm atie-rod 31., which Jiscon nected by way of a bifurcation which is notshown, to 1 a cross-beam 32 resting on theextended ends 8a of thescrewdown cross-beam 8. Bending cylinders 33i ini serted in thescrewdown cross-beam 8 act on thecrossr n beams such that the tie-rods31 are pulledupwards and I thus counter-bending is forced on the upperbacking roll 4 by way of the auxiliary bearing 30.The tie-rods 31 aredetachably connected to the cross-beam132,.in

order to be able to remove the screwdown cross-beam 8 laterally from thewindow '7 in. which it is guided 'at 1 1 right-angles.

What is claimed is: i 1

1. A roll stand comprising two lateral frames arranged in spacedparallel relationship; a window opening in each frame; a plurality ofchocks in said window openings; a plurality of rolls extending betweensaid lateral frames and journalled in said Chocks; a laterally re--movable screwdown cross-beam extending between 1 said lateral frames andthrough said1window'openings braced against the upper part of the frameby means of said thrust members.

2. A roll stand as claimed in claim 1, wherein the roll- 1 ing gap isadjustable by means of a hydraulicpistonwand1 1 cylinder deviceinterposed between each thrust member and the upper part of therespective frame, and fluid pressure transmitting means is associatedwith said piston and cylinder device, the weight of the fluid pressuretransmitting means and the piston and cylinder devices beingborne by thecross beam through said thrust members.

3. A roll stand as claimed in claim 2, wherein the cylinder of thepiston and cylinder devices are connected to a common plate on which thefluid pressure transmitting means are mounted.

4. A roll stand as claimed in claim 3, wherein each cylinder has abottom opening, each piston has a reroll.

1. A roll stand comprising two lateral frames arranged in spacedparallel relationship; a window opening in each frame; a plurality ofchocks in said window openings; a plurality of rolls extending betweensaid lateral frames and journalled in said chocks; a laterally removablescrewdown cross-beam extending between said lateral frames and throughsaid window openings between the top of each frame and an uppermostroll; and associated with each frame, a screw-down mechanism removablewith the cross beam and comprising: a nut fixedly mounted on the crossbeam, a thrust member in screw-threaded engagement with said nut, and adrive mechanism mounted on said cross beam for imparting a rotary motionto said thrust member while permitting movement thereof relative to saidnut; the cross beam in the screwed-down condition being braced againstthe upper part of the frame by means of said thrust members.
 2. A rollstand as claimed in claim 1, wherein the rolling gap is adjustable bymeans of a hydraulic piston and cylinder device interposed between eachthrust member and the upper part of the respective frame, and fluidpressure transmitting means is associated with said piston and cylinderdevice, the weight of the fluid pressure transmitting means and thepiston and cylinder devices being borne by the cross beam through saidthrust members.
 3. A roll stand as claimed in claim 2, wherein thecylinder of the piston and cylinder devices are connected to a commonplate on which the fluid pressure transmitting means are mounted.
 4. Aroll stand as claimed in claim 3, wherein each cylinder has a bottomopening, each piston has a reduced diameter end portion which projectsfrom the cylinder and is in sliding engagement with the connectingplate, said connecting plate being connected to lower end faces of thecylinders.
 5. A roll stand as claimed in claim 1, wherein ends of thecross beam project through the window openings in the lateral frames andare connected to the ends of the uppermost roll by connecting meansincluding hydraulic piston and cylinder devices which can be pressurizedto cause altering of the camber of the uppermost roll.